A RAINY wet season and a shaky wall have slowed uranium production at Ranger mine - with production expected to fall up to a thousand tonnes short by the end of the year.

Energy Resources Australia's (ERA's) quarterly review showed the mine produced 1828 tonnes of uranium oxide in the last three months - a 44 per cent drop from the same quarter last year.

It was also a 7 per cent fall on this year's first quarter.

The report blamed the instability on the south wall and an unusually rainy wet season, which flooded the pit and blocked access to the higher-grade uranium.

ERA chief executive Rob Atkinson said the company first reported a "very small movement" on the south wall nine months ago.

"It was only a couple of millimetres," he said.

"But, because of our focus on safety, we decided to back up to the top. Up at the top, there was more waste and lower-grade ore."

But Mr Atkinson said the mine was now dry and the wall stable, and the company expected to have access to the higher-grade ore - found at the lower levels of the pit - and increase uranium production for the second half of the year. But the poor performance for the first six months will see the mine fall short of expectations to meet last year's 5240-tonne target.

The mine is now expected to provide between 4300 and 4700 tonnes this year.

"We are obviously going to be targeting the upper limit of this range, if not higher," Mr Atkinson said.

ERA still believes it will meet all sales commitments, despite the shortfall, by selling more than 5000 tonnes of uranium ore.

Mr Atkinson said the company could meet these commitments by selling stockpiled uranium and being flexible with shipments.